There are currently numerous electrical connectors commercially available which are mounted to a printed circuit board. As the size of the machines in which the printed circuit boards are installed decreases, the density of the connectors positioned on the board must increase. Also, as the machines become more sophisticated, the complexity of the printed circuit boards and the connectors must increase. Consequently, the configuration of the machines requires that electrical connectors with numerous terminals extending therefrom be mounted on a printed circuit board in such a manner so as to occupy a minimal area of board real estate.
In order for the connectors to occupy a minimal amount of board real estate, it has become extremely desirable for connectors to have closely spaced terminals. To accomplish the required spacing, all dimensions of the connector must be minimized. However, the performance of the connector cannot be compromised due to the close centerline spacing of the terminals. It is therefore essential that the electrical characteristics of the connector not diminish as the size of the connector is reduced.
Consequently, in order to reduce the size of the connector while maintaining the electrical performance thereof, the present invention is directed to an enhanced ground bus. The ground bus requires minimal space, but provides the electrical characteristics to properly shield the closely spaced terminals of the connector. Such an enhanced ground bus is disclosed in U.S. Pat. No. 5,120,232, wherein matable ground bus bars are disposed in respective ones of matable plug and receptacle connectors. The matable section of a first one of the bus bars comprises staggered first and second mating portions along the connector length, with the first and second mating portions offset transversely, all in serpentine fashion; the matable section of the second bus bar comprises spaced first and second portions which are an array of spaced arms offset transversely which are deflected by the corresponding offset portions of the first bus bar and remain spring biased thereagainst after mating for an assured electrical connection therewith, in an interwoven arrangement. Additional mating arms of the first bus bar cooperate with the walls of the bus bar receiving recess of the connector housing to properly position bus bar for mating with the second bus bar. Each bus bar further includes an array of posts which extend from the respective connector housing to engage with ground circuits of the printed circuit board to which the connector is mounted.
Such connectors include signal contacts which are to be electrically interconnected to circuits of the printed circuit board by surface mounting, wherein the end or tail of the signal terminal is disposed atop a conductive pad of a respective board circuit along the adjacent major board surface, and preferably is soldered thereto. Since due to realities of manufacture and assembly of such connectors one or more of the contact tails is further from the respective pad than others, it is desired to apply force to urge or press the connector toward the board major surface during soldering to assure mechanical engagement between all contact tails and respective pads.
It is desired to provide the connector with integral means to generate mechanical securing of the connector prior to soldering, and requiring no additional hardware nor loose circuit board components to achieve presoldering hold-down.
It is desired to provide a ground bus with posts which facilitate mechanical securing of the connector to the printed circuit board prior to soldering.
It is also desired to provide such enhanced mechanical securing while not substantially increasing the forces necessary to mount the connector onto the board.